resolve: Pre-intern tool module bindings

Author: petrochenkov

compiler/rustc_resolve/src/ident.rs

@@ -572,8 +572,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                             )),
                         }
                     }
-                    Scope::ToolPrelude => match this.registered_tools.get(&ident).cloned() {
-                        Some(ident) => ok(Res::ToolMod, ident.span, this.arenas),
+                    Scope::ToolPrelude => match this.registered_tool_bindings.get(&ident) {
+                        Some(binding) => Ok((*binding, Flags::empty())),
                         None => Err(Determinacy::Determined),
                     },
                     Scope::StdLibPrelude => {

compiler/rustc_resolve/src/lib.rs

@@ -1006,6 +1006,7 @@ pub struct Resolver<'a, 'tcx> {
     dummy_binding: NameBinding<'a>,
     builtin_types_bindings: FxHashMap<Symbol, NameBinding<'a>>,
     builtin_attrs_bindings: FxHashMap<Symbol, NameBinding<'a>>,
+    registered_tool_bindings: FxHashMap<Ident, NameBinding<'a>>,
 
     used_extern_options: FxHashSet<Symbol>,
     macro_names: FxHashSet<Ident>,
@@ -1359,6 +1360,14 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     (builtin_attr.name, binding)
                 })
                 .collect(),
+            registered_tool_bindings: registered_tools
+                .iter()
+                .map(|ident| {
+                    let binding = (Res::ToolMod, pub_vis, ident.span, LocalExpnId::ROOT)
+                        .to_name_binding(arenas);
+                    (*ident, binding)
+                })
+                .collect(),
 
             used_extern_options: Default::default(),
             macro_names: FxHashSet::default(),